Elevating and tilting mechanisms of the general nature described hereinafter have typically employed worm screw arrangements. Such units are described in U.S. Pat. Nos. 2,850,054, 2,852,047 and 2,873,773. Although these units provide for an accurate setting of the tool in relation to the table top, the time necessary for the operator to arrive at the required tool elevation and bevel angle is often times unduly lengthy.
Further, these type mechanisms are generally intricately machined, and thus expensive, cumbersome and typically not conducive for on-site work by contractors or available for the homeowner for use around the house.
Rapid-set, lever-operated, elevating and tilting devices are also known. See, for example, U.S. Pat. Nos. 2,704,560; 2,719,547 and 3,670,788. Although the units described in the aforementioned patents have lever-operated arrangements, none of those cited above disclose a locking mechanism which can be manipulated by the same hand of the operator used to set the elevation of the blade. Further, none of those identified, suggest the inclusion of a vernier adjustment of the tool.
Finally, applicant is aware of a table saw presently marketed overseas, which includes a lever-operated, elevating mechanism having means for locking the lever to the housing at the desired blade elevation setting. Further, this table saw includes a vernier adjust feature which is disposed on the lever and activated through rotation of the lever grip.
The table saw also includes means for varying the angular relationship between the tool and the work surface. However, in this table saw, it is the work surface table portion thereof which is pivotally mounted on the housing. The fact that the work surface tilts, limits the application of such a machine in that relatively long pieces of lumber and the like can't be cut at larger bevel angles because the floor on which the table saw stands, acts as an obstruction. This generally precludes application of such a device to on-site work by the small contractor or homeowner and, hence, limits its general application.
It is, therefore, a primary object of this invention to provide a power tool apparatus which allows for one-hand, coarse and vernier adjustment of the tool elevation setting and which further provides a lever-operated, tilt mechanism wherein the tool support assembly is pivoted relative to a stationary, horizontal work surface.
It is still a further object of this invention to provide a power tool apparatus which achieves the accuracy of worm gear type units, but which provides quick setting of the elevation angle of the tool.
It is yet another object of this invention to provide a locking mechanism, disposed on the elevation setting lever, which is manipulated by the same hand.
It is yet a further object of this invention to provide a power tool apparatus which employs a relatively simple, vernier adjust mechanism.
It is still another object of this invention to provide a power tool apparatus which because of its relatively simple design, is mass producible at a cost which makes it readily available to the small contractor or homeowner.
It is yet another object of this invention to provide in one embodiment, a compact, portable apparatus which is aptly suited for practically all types of on-site work encountered by the small contractor or homeowner.
It is still a further object in one application of the invention to provide the above-mentioned power tool apparatus in the form of a table saw which is low cost, and which meets the needs of the small contractor or homeowner.